It would be interesting to know how important the ARM instruction set is to Apple.
Seriously though, I suspect that the ISA isn't that important for Apple but on the other hand I think they're probably quite happy with the direction of the Arm ISA (probably had a big say in parts of it) and it would take quite a lot to push them away.
I think that the odds on the Nvidia takeover are quite small by now so don't think a move likely at all.
Will RISC V do what ARM did to x86? Start at the low end, be more open, and slowly take over.
Agree with the point 100% but Apple also has a history of long and sustained investments in key parts of the stack where it sees long term value - including compilers and silicon - and long relationships with suppliers. I suspect their relationship with Arm is in that category and so in the absence of something that is demonstrably better, then that will continue.
The Nvidia purchase is irrelevant to Apple. They have a license that won’t be impacted.
The only thing that would make them move away would be a performance bottleneck in the architecture that necessitates a shift.
Large companies like Apple have an architectural license and implement the entire instruction set on their own.
I worked for a couple of companies with ARM architectural licenses and there was a large ARM compliance suite of tests that had to be run and pass before you could claim that you made an ARM instruction set compatible CPU.
I have heard that Apple does not claim ARM compatibility and doesn't run the compliance suite which allows them a few shortcuts and other optimizations. Apple only cares about running Mac OS and iOS on their hardware so if they were incompatible with Linux/ARM or Windows/ARM they wouldn't really care.
I haven't been able to verify this. Linux/ARM seems to be running okay so far on the new Apple M1 chips.
I don't know if Apple would be affected much if Nvidia buys ARM. Their architecture license to implement from scracth is probably forever but maybe not
